Process of stretching leather.



i. H. EiLSWORTH.

PROCESS OF STRETCHING LEATHER.

APPLICAHON FEE!) FE B. 2 I917- Patented July 31, 191?.

INVENTUE' IRVING H. ELLSWORTH, OF ORR-VILLE, OHIO.

PROCESS OF STRETGHING LEATHER.

Specification of Letters Patent.

Patented July 31, 1917.

App1ication filed February 2, 1917. SerialNo. 146,192.

To all whom it may concern:

Be it known that I, IRVING H. ELLswoRTH, a citizen of the United States, and a resident of Orrville, in the county of WVayne and State of Ohio, have invented a certain new and useful Process of Stretching Leather; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to the characters of reference marked thereon, which form a part of this specification.

This invention relates to the treatment of leather, and particularly to an improved process for stretching the same. 7

Leather is composed of more or less closely interwovenfibers and the pores or minute spaces between the fibers are filled with the stufling material which may comprise tallow, stearin, paraflin, wax, oils or the like, as well understood in the art. Stretching the leather lengthwise of the grain causes the fibers thereof to fit more closely together and tends to force out the stufling material if.

mellowed sufficiently for such purpose. The stuifing materials being solid, however, when in a cold state, remain to a greater or less extent between the fibers during a stretching operation and resist a close fitting together of the same and a consequent full stretching of the leather. The mellowing process customarily employed in preparing leather for stretching consists in soaking the leather in water. The resistance to stretching ofiered by the presence of the stuiiing material in the leather is partly overcome by this watersoaking process but not to such an extent as to permit a full stretching of the leather or the displacing of the stufling material by the leather fibers. In other words, the watersoaking does not soften the stufiing material to such an extent that it becomes a yielding, plastic or non-resistant substance so that it will yield easily to a drawing together of the fibers in the leather when subjected to a stretchin strain.

The ob ect of my invention is to so stretch and treat leather preparatory therefor that the entire stretch may be taken out of the leather in a simple, thorough and eflicient manner.

The invention is fully described in. the following specification, and while it is capable of being practised in numerous ways, a

preferred means for practising the same is illustrated in the accompanying drawings, in which Figure l is a perspective view of a cabinet in which leather may be subjected to heat to mellow the same, a portion of the cabinet being broken away, and Fig. 2 is a perspective View of an apparatus for stretching the leather strips after being taken from the mellowing cabinet.

In practising my process, leather strips of any desired size to be stretched are placed in the cabinet and preferably subjected to a steam or vapor heating treatment to soften the stu'liing material contained therein. In Fig. 1, 1 designates a cabinet which may be closegl to render the same substantially steam-tight and which contains water 2 in its bottom portion and a false perforated or lattice-work bottom 3 above the water 2 in which. the leather strips 4 may he stood in edgewise position. A gas burner 5 or other suitable heating means is disposed below the cabinet to eifect a heating of the water 2. The heat within the cabinet is raised to a sufficient temperature to reduce the stuffing material contained in the leather to a plastic, yielding or non-resistant state, and inasmuch as different stuffing materials require different temperatures to soften the same, no specific temperature can be given or the heating of the leather. The heat usually employed, however, for mellowing the stuiiing material of leather is around 110 Fahrenheit. Some materials, however, for instance, lard, will melt at a very much less degree of heat so that no fixed rule can be laid down for the temperature to be employed. The main thing to be borne in mind in this connection is that only sufficient heat is required to render plastic the kind of stuffing material used.

It is preferable to employ a steam'or Wet heat, as better results are obtained than when employing a dry heat for mellowing the stuffing materials contained in the leather.

When the leather has been sufiiciently mellowed in the heat bath the strips are taken out as desired and subjected to a stretching operation, as illustrated by the stretching apparatus shown in Fig. 2, any suitable type of which may be employed. This stretching is performed While the leather is in its heated or mellow state so that the fibers are permitted to be drawn closely together during the stretching operation and to displace geal or assume a permanent set form, the

time required for this in a Warm room being approximately fifteen minutes. \Vhen the leather is stretched after the ordinary Water mellowing process it is necessary to leave it on the stretching device until it dries which requires seyeral hours.

The advantages of my improvedmellon'ing process over those heretofore used preparatory to stretching leather may be enumerated as follows:

First. Thestuliing material oii'ers a minimum of resistance to the stretching action.

Second. There is no loss of stutling mate rial as'in the Water-soaking process.

Third. The time required for stretching and a permanent setting of the stretched leather is materially shortened.

Fourth. The stretching can be more easily and thoroughly performed.

Fifth. Less space for handling andaless labor required.

I Wish it understood that my invention is not limited to the details described and to the use oi apparatus of the class described but is capable of numerous modifications Without departing from the spirit of the claims.

Having thus described my invention, What I claim as new, and desire to secure by Letters Patent, is

1. The process of stretching strips 0t heavy stutl'ed leather such as used for har- Wet heat to the leather to render ,the stul'ling material therein plastic and yielding, then stretching the leather lengthwise ot' the strips while in a heated state thereby causing an enudation oi stutting material from the leather, andthen allowing the strips to cool and set While under tension.

In testimony whereof I have hereunto signed my name to this specification.

IRVING H. ntnswonrn.

Copies of this patent may be obtained for five cents each, lay-addressing the Commissioner of Patents. Washington, fl). 6. 

